Kinetic studies in two areas of biochemistry are being carried out. These are: the kinetic role of metal ion in physical systems, and the dynamics of elementary steps in enzymes. The specific research to be accomplished involves the kinetics of divalent metal ion interactions with nucleotide, dinucleotide, and flavin coenzymes; the kinetics of metal ion association with enzymes and enzyme-coenzyme systems; and kinetic studies of rapid processes in aqueous enzymes such as ribonuclease, hexokinase and deoxyribonuclease. The long-term objectives of the research are: 1. to elucidate the mechanisms of action of enzymes by studying the rapid elementary steps which constitute the total reactions; 2. to establish the kinetic roles of labile metal ions in enzymatic systems; and 3. to characterize the rates and mechanisms of metal ion interactions with nucleotides and other coenzymes. A wide variety of rapid kinetic instrumentation is being brought to bear upon these problems. Methods to be used include rapid stopped flow as well as relaxation spectroscopy (especially T-jump and ultrasonics).